Searched for: author:"Sheldon, R.A."
(1 - 18 of 18)
document
Sheldon, R.A. (author)
Biocatalysis has emerged in the last decade as a pre-eminent technology for enabling the envisaged transition to a more sustainable bio-based economy. For industrial viability it is essential that enzymes can be readily recovered and recycled by immobilization as solid, recyclable catalysts. One method to achieve this is via carrier-free...
journal article 2019
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Sheldon, R.A. (author)
The pressing need for climate change mitigation has focused attention on reducing global emissions of carbon dioxide by effectuating the transition from fossil-based chemicals manufacture to a carbon neutral alternative based on lignocellulosic waste. The first step involves fractionation of the lignocellulose into cellulose, hemicellulose,...
review 2018
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Sheldon, R.A. (author), Woodley, John M. (author)
review 2018
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Sheldon, R.A. (author)
The first green chemistry metrics - the E factor (kgs waste/kg product) and atom economy (mol wt of product/sum of mol wts of starting materials) - were introduced in the early 1990s and were actually green chemistry avant la lettre. In the last two decades, these two metrics have been adopted worldwide by both academia and industry. The E...
review 2018
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Sheldon, R.A. (author)
The conversion of sugars, derived from waste polysaccharide biomass, to commodity chemicals by fermentation or catalytic hydrogenation, oxidation or dehydration or combinations thereof are reviewed.
review 2018
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Sheldon, R.A. (author), Van Pelt, S. (author)
In this tutorial review, an overview of the why, what and how of enzyme immobilisation for use in biocatalysis is presented. The importance of biocatalysis in the context of green and sustainable chemicals manufacture is discussed and the necessity for immobilisation of enzymes as a key enabling technology for practical and commercial viability...
journal article 2013
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Sheldon, R.A. (author)
Cross-linked enzyme aggregates (CLEAs) have many economic and environmental benefits in the context of industrial biocatalysis. They are easily prepared from crude enzyme extracts, and the costs of (often expensive) carriers are circumvented. They generally exhibit improved storage and operational stability towards denaturation by heat, organic...
journal article 2011
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Sheldon, R.A. (author)
public lecture 2007
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Sheldon, R.A. (author)
The key to obtaining an optimum performance of an enzyme is often a question of devising an effective method for its immobilization. In the present review, we describe a novel, versatile and effective methodology for enzyme immobilization as CLEAs (cross-linked enzyme aggregates). The method is exquisitely simple (involving precipitation of the...
journal article 2007
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Kroon, M.C. (author), Shariati, A. (author), Florusse, L.J. (author), Peters, C.J. (author), Van Spronsen, J. (author), Witkamp, G.J. (author), Sheldon, R.A. (author), Gutkowski, K.I. (author)
The invention is directed to a process for carrying out a chemical reaction in an ionic liquid as solvent and CO2 as cosolvent, in which process reactants are reacted in a homogeneous phase at selected pressure and temperature to generate a reaction product at least containing an end-product of the reaction, and upon completion of the reaction a...
patent 2006
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Lopez Serrano, P. (author), Cao, L. (author), Van Rantwijk, F. (author), Sheldon, R.A. (author)
The invention relates to a method of preparing cross-linked enzyme aggregates (CLEAs) comprising the steps of a) precipitating a dissolved enzyme present in a liquid medium; b) cross-linking with a cross-linker, and c) optionally, washing the cross-linked enzyme aggregate. According to the invention at least one treatment is performed chosen...
patent 2002
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Dijksman, A. (author), Arends, I.W.C.E. (author), Sheldon, R.A. (author)
The invention relates to a method of oxidizing an alcohol to form an aldehyde or ketone using a ruthenium ion and oxygen in the presence of a substantially stable N-O free radical compound, wherein two atoms bound to the nitrogen atom are not themselves hydrogen carriers. It has been found that with such a combination of a ruthenium ion and...
patent 2000
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Verspui, G.A. (author), Sheldon, R.A. (author)
Use of an acid catalyst to improve yields in the preparation of polyketones in aqueous medium by polymerising a mixture of CO and alkylenically unsaturated hydrocarbons in the presence a catalyst composition comprising a group VIII metal and a ligand. Process for preparing a polyketone in aqueous medium by polymerising a mixture of CO and an...
patent 1999
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Dakka, J. (author), Sheldon, R.A. (author), Sanderson, W.A. (author)
Abstract of GB 2309655 (A) Heterogeneous catalysts comprising one or more metal compounds selected from the group consisting of tin, molybdenum, tungsten, zirconium and selenium compounds deposited on the surface of a silicalite are provided. Preferably Sn(IV) and/or Mo(VI) are employed. The catalysts are prepared by reacting a metal halide...
patent 1997
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De Zoete, M.C. (author), Van Rantwijk, F. (author), Sheldon, R.A. (author)
Abstract of WO 9507359 (A1) A process for carrying out enzymatically catalyzed conversions of organic compounds comprises reacting an ester of an organic acid in a liquid organic phase with ammonia in the presence of a hydrolytic enzyme such as a lipase, esterase or protease. The process permits the highly enantioselective preparation of...
patent 1995
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Sheldon, R.A. (author), DONG, C.J. (author), JIHAD, D. (author)
Abstract of WO 9417021 (A1) The invention relates to an improvement in the practice of a catalyzed autoxidation of a starting material selected from (cyclo)alkanes, (cyclo)alkyl aromatics and alcohols derived therefrom. The improvement consists in the autoxidation being carried out by allowing oxygen to act on the employed starting material in...
patent 1994
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Sheldon, R.A. (author), Chen, J.D. (author), Dakka, J. (author)
Abstract of WO 9408932 (A1) The invention relates to an improvement in carrying out a catalyzed decomposition of organic hydroperoxides. The improvement consists in the use of a heterogeneous catalyst which is composed of a three-dimensional microporous structure, a so-called molecular sieve, containing aluminum, silicon and/or phosphorus oxides...
patent 1994
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Sheldon, R.A. (author)
public lecture 1993
Searched for: author:"Sheldon, R.A."
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